Aromatic cyanate esters derived from bisphenol A exhibit high glass transition temperatures, but suffer from high dielectric constants and vulnerability to moisture attack. Aromatic cyanate esters derived from hydrocarbon (dicyclopentadienyl) phenols offer improved moisture resistance and electrical properties, but lack flame retardancy required in many electrical laminate applications. It would therefore be desirable to have hydrocarbon phenol cyanate resins which exhibit some flame retardancy.